1. Field of the Invention
This invention relates generally to methods and systems for hydraulically transporting solids, and more particularly, but not by way of limitation, to methods and systems of apparatus for forming a particulated solids-carrier liquid slurry and transporting it through a conduit.
2. Description of the Prior Art
In the mining and transport of minerals such as coal as well as in other applications where it is required to transport solids to a remote location, hydraulic transport of the solids, i.e., forming the solids into a slurry and pumping the slurry through a conduit has heretofore been developed and used successfully. Generally, such hydraulic solids transportation systems have included a mixing tank wherein the solids to be transported, after being crushed to a desired size, are introduced and combined with a stream of carrier liquid to form a pumpable slurry. The slurry is continuously pumped from the tank through a conduit to a remote location. The flow rate of the slurry pumped through the conduit as well as the concentration of solids contained in the slurry have generally heretofore been uncontrolled, controlled manually, or partially automated, and problems have been encountered when the concentration of solids in the slurry becomes too high or the flow rate of slurry through the conduit too low in that either of these conditions will allow the solids to settle out of the slurry and deposit in the conduit. In order to overcome these problems, prior systems have often been operated using excess slurry flow rates with inefficient results.
In hydraulically transporting minerals such a coal from the working face in a mine to a terminus located either within the mine or outside the mine, problems associated with the control of the solids concentration in the slurry and the velocity of the slurry through the conduit in which it is being transported are acute. Because mining machines removing coal from the working face of a mine do not produce a constant flow of coal, when the coal is crushed and introduced into a sump wherein a coal-carrier liquid slurry is formed the concentration of coal in the slurry varies over a wide range, often from 0% to over 50% by volume. Heretofore, the flow rate of carrier liquid combined with the crushed coal to form the slurry has been controlled manually and the flow rate of slurry through the conduit transporting it to a remote location has varied, often leading to problems associated with plugging the conduit due to too high a solids concentration or too low a slurry flow rate.
By the present invention methods and systems for forming a particulated solids-carrier liquid slurry and transporting it through a conduit are provided wherein such problems associated with inadequate control of the solids concentration in the slurry and flow rate of the slurry through the transporting conduit are obviated.